I think that's a good sign. It probably means the problem is being dealt with by admins. Any communities on the affected instances that have subscribers on other instances will be backed up on those other instances, so most of the content is safe no matter what. I just hope the users on those instances know they can come to others in the meantime.
From the few bits I've read, it sounds like the issue is spreading through comments and involves the markdown parser. This needs dev intervention, not just admins.
It may well be that the lemmy.world admin account was compromised as a result of the hack, rather than to make it happen.
Apparently Memmy is immune to this, not sure about other apps. Someone else advised staying loggged out, and maybe be prepared to change your password after it's resolved.
FWIW, right now it seems unlikely that your password was accessible to anyone. Your login cookie may have been taken if you accessed Lemmy on a web browser (apps are likely fine), so you would want to clear your Lemmy cookies and cache once this is over.
But I'm speculating, and changing your password will definitely help!